--- a/rust/hg-core/src/repo.rs	Fri Sep 03 16:32:35 2021 +0200
+++ b/rust/hg-core/src/repo.rs	Mon Sep 06 11:39:59 2021 +0200
@@ -1,12 +1,11 @@
 use crate::config::{Config, ConfigError, ConfigParseError};
-use crate::errors::{HgError, IoErrorContext, IoResultExt};
+use crate::errors::HgError;
 use crate::exit_codes;
 use crate::requirements;
 use crate::utils::files::get_path_from_bytes;
 use crate::utils::SliceExt;
-use memmap::{Mmap, MmapOptions};
+use crate::vfs::{is_dir, is_file, Vfs};
 use std::collections::HashSet;
-use std::io::ErrorKind;
 use std::path::{Path, PathBuf};
 
 /// A repository on disk
@@ -38,12 +37,6 @@
     }
 }
 
-/// Filesystem access abstraction for the contents of a given "base" diretory
-#[derive(Clone, Copy)]
-pub struct Vfs<'a> {
-    pub(crate) base: &'a Path,
-}
-
 impl Repo {
     /// tries to find nearest repository root in current working directory or
     /// its ancestors
@@ -251,66 +244,3 @@
         Ok(parents)
     }
 }
-
-impl Vfs<'_> {
-    pub fn join(&self, relative_path: impl AsRef<Path>) -> PathBuf {
-        self.base.join(relative_path)
-    }
-
-    pub fn read(
-        &self,
-        relative_path: impl AsRef<Path>,
-    ) -> Result<Vec<u8>, HgError> {
-        let path = self.join(relative_path);
-        std::fs::read(&path).when_reading_file(&path)
-    }
-
-    pub fn mmap_open(
-        &self,
-        relative_path: impl AsRef<Path>,
-    ) -> Result<Mmap, HgError> {
-        let path = self.base.join(relative_path);
-        let file = std::fs::File::open(&path).when_reading_file(&path)?;
-        // TODO: what are the safety requirements here?
-        let mmap = unsafe { MmapOptions::new().map(&file) }
-            .when_reading_file(&path)?;
-        Ok(mmap)
-    }
-
-    pub fn rename(
-        &self,
-        relative_from: impl AsRef<Path>,
-        relative_to: impl AsRef<Path>,
-    ) -> Result<(), HgError> {
-        let from = self.join(relative_from);
-        let to = self.join(relative_to);
-        std::fs::rename(&from, &to)
-            .with_context(|| IoErrorContext::RenamingFile { from, to })
-    }
-}
-
-fn fs_metadata(
-    path: impl AsRef<Path>,
-) -> Result<Option<std::fs::Metadata>, HgError> {
-    let path = path.as_ref();
-    match std::fs::metadata(path) {
-        Ok(meta) => Ok(Some(meta)),
-        Err(error) => match error.kind() {
-            // TODO: when we require a Rust version where `NotADirectory` is
-            // stable, invert this logic and return None for it and `NotFound`
-            // and propagate any other error.
-            ErrorKind::PermissionDenied => Err(error).with_context(|| {
-                IoErrorContext::ReadingMetadata(path.to_owned())
-            }),
-            _ => Ok(None),
-        },
-    }
-}
-
-fn is_dir(path: impl AsRef<Path>) -> Result<bool, HgError> {
-    Ok(fs_metadata(path)?.map_or(false, |meta| meta.is_dir()))
-}
-
-fn is_file(path: impl AsRef<Path>) -> Result<bool, HgError> {
-    Ok(fs_metadata(path)?.map_or(false, |meta| meta.is_file()))
-}